Treatment method for ternary material and method for improving capacity and cycle performance of lithium battery

Abstract

The invention discloses a treatment method for a ternary material LiNixCoyMnzO2(x+y+z). The method comprises the following steps of: firstly, adjusting the pH value of a LiNixCoyMnzO2 material to be alkaline or strongly alkaline and range from 8.0 to 12.0; secondly, gradually adding a cobalt salt solution into the alkaline or strongly alkaline LiNixCoyMnzO2 turbid liquid; and finally, drying the mixed material, adding a proper amount of lithium salt, and firing the mixture for 5 to 24 hours at a proper temperature in an air atmosphere to prepare the LiNixCoyMnzO2 material with a LiCoO2 treated surface. The method is simple in process; and the prepared product has high electrochemical performance within a high voltage range and is favorable for large-scale production.

Description

technical field

[0001] The invention relates to the technical field of lithium-ion batteries, in particular to a ternary material processing method, the ternary material obtained by the processing method, and a method for improving the capacity and cycle performance of a lithium-ion battery with the ternary material as the positive electrode material, The ternary material is LiNi x co y mn z o 2 , x+y+z=1. Background technique

[0002] Lithium-ion secondary batteries have many advantages such as long cycle life, stable discharge voltage, large specific capacity, and no memory effect, making them widely used in many fields such as mobile phones, notebook computers, and portable electronic devices, and are increasingly popular among the public. Attention and favor.

[0003] In 2001, Japanese scientist T. Ohzuku's research group synthesized Li(Ni 1 / 3 co 1 / 3 mn 1 / 3 )O 2 positive electrode material, and reported its electrochemical performance as a lithium ion battery po...

Examples

preparation example Construction

[0033] (2) Preparation of surface treatment materials:

[0034] Configure a cobalt salt solution with an appropriate concentration of preferably 1-10mol / L, and gradually add the cobalt salt solution to the above-mentioned LiNi with adjusted pH value under constant stirring. x co y mn z o 2 (x+y+z=1) suspension. And fully react at room temperature under constant stirring, preferably for 1-5 hours, and then preferably dry in an oven at 100-150°C.

[0035] Adding cobalt salt is in order to introduce cobalt element, so as long as all soluble cobalt salts that can be burned and removed by other elements except cobalt in the follow-up burning process can be applicable to the present invention, such as, can select cobalt acetate salt, citric acid for use At least one of cobalt salt or cobalt nitrate salt.

[0036] (3) Preparation of final material:

[0037] Add an appropriate amount of lithium salt to the dried material, mix thoroughly, and fully ignite in an air atmosphere at ...

Embodiment 1

[0044] Accurately weigh 200g LiNi 0.4 co 0.2 mn 0.4 o 2 Add appropriate amount of water to the ternary powder material to adjust it to a muddy state, configure an ammonia solution with a concentration of 10mol / L, and mix 200gLiNi with constant stirring 0.4 co 0.2 mn 0.4 o 2 The pH value of the suspension was adjusted to 11.0 to make the mixture strongly alkaline, and 20g Co(NO 3 ) 2 The concentration of the solution was adjusted to 10mol / L. Under the condition of constant stirring, the cobalt salt solution was gradually added into the adjusted LiNi 0.4 co 0.2 mn 0.4 o 2 Suspension. When the cobalt salt solution is completely added to the LiNi 0.4 co 0.2 mn 0.4 o 2 When in the suspension, the reaction is continued for 5 hours at room temperature under constant stirring, and the precursor prepared by the reaction is dried in an oven at 100-150°C. Finally, 2.5g of LiOH powder was accurately weighed, and the dried precursor and LiOH powder were evenly mixed and the...

Embodiment 2

[0046] Accurately weigh 200g LiNi 0.4 co 0.2 mn 0.4 o 2 Add appropriate amount of water to the ternary powder material to adjust it to a muddy state, configure an ammonia solution with a concentration of 10mol / L, and mix 200gLiNi with constant stirring 0.4 co 0.2 mn 0.4 o 2 The pH value of the suspension was adjusted to 11.0 to make the mixture strongly alkaline, and 27.5g Co(NO 3 ) 2 The concentration of the solution was adjusted to 10mol / L. Under the condition of constant stirring, the cobalt salt solution was gradually added into the adjusted LiNi 0.4 co 0.2 mn 0.4 o 2 Suspension. When the cobalt salt solution is completely added to the LiNi 0.4 co 0.2 mn 0.4 o 2 When in the suspension, the reaction is continued for 5 hours at room temperature under constant stirring, and the precursor prepared by the reaction is dried in an oven at 100-150°C. Finally weigh 5.6gLi accurately 2 CO 3 powder, the dried precursor and Li 2 CO 3 The powder is mixed evenly and ...

technical field

[0001] The invention relates to the technical field of lithium-ion batteries, in particular to a ternary material processing method, the ternary material obtained by the processing method, and a method for improving the capacity and cycle performance of a lithium-ion battery with the ternary material as the positive electrode material, The ternary material is LiNi x co y mn z o 2 , x+y+z=1. Background technique

[0002] Lithium-ion secondary batteries have many advantages such as long cycle life, stable discharge voltage, large specific capacity, and no memory effect, making them widely used in many fields such as mobile phones, notebook computers, and portable electronic devices, and are increasingly popular among the public. Attention and favor.

[0003] In 2001, Japanese scientist T. Ohzuku's research group synthesized Li(Ni 1 / 3 co 1 / 3 mn 1 / 3 )O 2 positive electrode material, and reported its electrochemical performance as a lithium ion battery po...

Examples

preparation example Construction

[0033] (2) Preparation of surface treatment materials:

[0034] Configure a cobalt salt solution with an appropriate concentration of preferably 1-10mol / L, and gradually add the cobalt salt solution to the above-mentioned LiNi with adjusted pH value under constant stirring. x co y mn z o 2 (x+y+z=1) suspension. And fully react at room temperature under constant stirring, preferably for 1-5 hours, and then preferably dry in an oven at 100-150°C.

[0035] Adding cobalt salt is in order to introduce cobalt element, so as long as all soluble cobalt salts that can be burned and removed by other elements except cobalt in the follow-up burning process can be applicable to the present invention, such as, can select cobalt acetate salt, citric acid for use At least one of cobalt salt or cobalt nitrate salt.

[0036] (3) Preparation of final material:

[0037] Add an appropriate amount of lithium salt to the dried material, mix thoroughly, and fully ignite in an air atmosphere at ...

Embodiment 1

[0044] Accurately weigh 200g LiNi 0.4 co 0.2 mn 0.4 o 2 Add appropriate amount of water to the ternary powder material to adjust it to a muddy state, configure an ammonia solution with a concentration of 10mol / L, and mix 200gLiNi with constant stirring 0.4 co 0.2 mn 0.4 o 2 The pH value of the suspension was adjusted to 11.0 to make the mixture strongly alkaline, and 20g Co(NO 3 ) 2 The concentration of the solution was adjusted to 10mol / L. Under the condition of constant stirring, the cobalt salt solution was gradually added into the adjusted LiNi 0.4 co 0.2 mn 0.4 o 2 Suspension. When the cobalt salt solution is completely added to the LiNi 0.4 co 0.2 mn 0.4 o 2 When in the suspension, the reaction is continued for 5 hours at room temperature under constant stirring, and the precursor prepared by the reaction is dried in an oven at 100-150°C. Finally, 2.5g of LiOH powder was accurately weighed, and the dried precursor and LiOH powder were evenly mixed and the...

Embodiment 2

[0046] Accurately weigh 200g LiNi 0.4 co 0.2 mn 0.4 o 2 Add appropriate amount of water to the ternary powder material to adjust it to a muddy state, configure an ammonia solution with a concentration of 10mol / L, and mix 200gLiNi with constant stirring 0.4 co 0.2 mn 0.4 o 2 The pH value of the suspension was adjusted to 11.0 to make the mixture strongly alkaline, and 27.5g Co(NO 3 ) 2 The concentration of the solution was adjusted to 10mol / L. Under the condition of constant stirring, the cobalt salt solution was gradually added into the adjusted LiNi 0.4 co 0.2 mn 0.4 o 2 Suspension. When the cobalt salt solution is completely added to the LiNi 0.4 co 0.2 mn 0.4 o 2 When in the suspension, the reaction is continued for 5 hours at room temperature under constant stirring, and the precursor prepared by the reaction is dried in an oven at 100-150°C. Finally weigh 5.6gLi accurately 2 CO 3 powder, the dried precursor and Li 2 CO 3 The powder is mixed evenly and ...

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